I've had a very quick test and can't replicate that problem. What happens? Do you see an error message or does the mail just not get to the tps_user_message table? Is this a prompted or hard-coded criteria? If you take the criteria off do the query results email as expected?
Sorry for all the questions,
No error messages
The mails are in the message table (sent & failed both 0)
Any query with dates in the criteria will not send!
Would you mind logging this with Support please? I think we'll need to investigate this one.